Manipulator



pltilzo, 1948. A L B BENSEN 2,440,067

MANIPULATOR Filed Nov. 10, 1945 Inventor: 15g@A B. Bensen,

His Attorney.

Patented Apr. 20, 1948 UNITED vSTATES 1 i\:1r.1\rr` olf-FICE New York Application November 1o, 1945, serial No. 627,952

My invention relates to; positioning means and,

more particularly, to devices for manipulating or lcontrolling the position of an article.

It is frequently desirable, for example in microscopy, to control the position of an article or element to be examined. Thus, in electron optical instruments, for example an electron diffraction instrument, it is desirable to control not only the position of` an article or specimen to be examined, but it is also important that the specimen be capable of being moved in various independent directions to control the point of incidence of an electron beam, as well as the angle of incidence of that beam on the specimen. It is, furthermore, important to provide mechanisms which permit precise and minute adjustment of the specimen position through three degrees of translation and two degrees of rotation and which obtain such manipulation without involving complex mechanisms. Thus, it is desirable not only to reduce the expense of manufacturing such mechanisms, but also to maintain the size as small as possible so that it is not large and cumibersome in comparison with the specimen to be examined, particularly since in such work the manipulator usually is maintained Within an evacuated Vessel or container. It is desirable that the dimensions be as small as possible to reduce the time and cost of evacuating the apparatus.

It is an obj ect of my invention to provide a new and improved positioning device or manipulator.

It is another object of my invention to provide a new and improved positioning device or manipulator which is simple in construction and arrangement and which is capable of precisely positioning an object to be investigated in three degrees of translation and two degrees of rotation.

It is a further object of my invention to provide a new and improved manipulator comprising two coaxial shafts which are independently rotatable and the axis'of which may be varied precisely to position a specimen relative to three degrees of translation and two degrees of rotation.

Briefly stated, in the illustrated embodiment of my invention, I provide a manipulator oropositioning device for controlling and holding an article or object and which is susceptible of producing rotation about two angularly disposed axes andthe common axis of which is variable in position so that the position of a supported article may be controlled precisely through three mutually perpendicular directions of translation as well as two degrees of rotation.

For a better understanding of my invention, reference may bey had to the following description' taken in connection with the accompanying drawing and its scope will be pointed out in the o A1oy claims. (c1. 2505495)- appended claims. Fig. 1 is a side elevation view of an electron diffraction instrument suitably embodyingthe invention. Figs. 2 and 3 are perspective and vertical sectional views, respectively, of the manipulator employed in the instrument of Fig. 1.

Referring now to Fig. 1, there is shown a portion of an electron diffraction instrument which comprises a control panel I behind which is located an electron gun, not shown, for projecting a beam of electrons through an evacuated tube 2. rThe electronbeam is focussed by means of a focussing yoke 3, which may be of the magnetic type, to fall upon a specimen to be examined and supported on a. suitable article carrier 4. The electron beam may either be reflected from the specimen or may "be allowed to pass through the specimen, if it is a very thin one, to form a diffraction pattern upon a fluorescent screen 5. Alternatively, the pattern may be formed upon a photographic plate or lm located within an evacuated film holder 6. The specimen holder 4 is arranged .within a specimen chamber 'I having a hinged crystalline structure of a specimen being examined it is desirable to control ,the point of incidence of the electron beam on the specimen, as well as the angle of incidence in the case of a reflected beam, a manipulator or positioning means 9 is provided for varying the position of the specimen support 4 through two degrees of rotation and three degrees of translation.

Referring now to Figs. 2 and 3 jointly, the manipulator 9 is illustrated as comprising a cylindrical casing I0 which is adapted to be secured to the upper surface of the specimen chamber 1 'by a plurality of screws II. The casing I0 is externally threaded and is surrounded by an internally threaded cylinder I'2.' A plate member I3 is supported on the upper surface of the cylinder I2 by a. ball bearing I4, the race of which may be formed integrally in the upper surface of the cylinderl2 and the lower surface of the plate I3. A retaining ring I5 for the ball bear- 4ings Il is interposed between the adjacent surfaces of the members I2, I3. The members I2, I3 may be held in assembled position by an assembly ring I'B which is adapted to be screwed vto the cylinder I2.

frame member supported by one of said shafts for rotation thereby about a, rst axis, article supporting means including a shaft supported by said member and arranged to be rotated by the other of said shafts about an axis inclined at an angle to said first axis, means for varying the position of said frame member along the axis of said pair of shafts, and means for varying the position of the axis of said pair of shafts relative to said shaft supporting means.

3. In a Ipositioning device, the combination comprising a pair of coaxial shafts, means supporting s-aidl shafts, an article supporting member supported by one of said shafts and arranged to be rotated about a rst axis thereby, means including a shaft mechanically connected to the other of said pair of shafts for rotating said article supporting member about an axis inclined at an angle to said first axis, and means for varying the position of the axis of said pair of shafts relative to said shaft supporting means.

4. In a positioning device capable of providing rotating motions along two non-parallel axes, the combination comprising a pair of coaxial shafts, means for supporting said shafts, a frame member supported by one of said shafts and arranged to be rotated thereby, an article supporting member journalled in said frame member, means mechanically linking the other of said shafts and said article supporting member for rotation about an axis inclined at an angle with respect to the common axis of said pair of shafts, and means for varying the position of the axis of said pair of shafts with respect to said supporting means comprising a rpair of independently adjustable members interposed between said supporting means and said pair of shafts.

5. A positioning device comprising a pair of coaxial shafts, means for supporting said shafts, a rod supported at one end of said shafts and inclined at an angle to the axis thereof, article supporting means supported on said rod, means for moving said rod longitudinally of said axis, means utilizing one of said shafts for rotating said article supporting means about the axis of said rod, and means utilizing the other of said shafts for rotating said article supporting means about the axis of said shafts.

6. A positioning device comprising a pair of coaxial shafts, means for supporting said shafts, a rod supported at one end of said shafts and inclined at an angle to the axis thereof, article supporting means supported on said rod, means for moving said rod longitudinally of said axis, means utilizing one of said shafts for rotating said article supporting means about the axis of said rod, means utilizing the other of said shafts for rotating said article supporting means about the axis of said shafts, and means for varying the position of the axis of said pair of shafts relative to said shaft supporting means.

7. In a device for controlling the position of an article within an evacuated enclosure, the combination comprising a pair of coaxial shafts extending Within said enclosure, means including a resilientportion for supporting said shafts, said shafts having respective externally accessible parts, means for compressing said resilient portion to vary the axial position of said shafts, means for controlling the angular position of said shafts relative to their axis, article supporting means supported by one of said shafts at a point remote from the externally accessible part thereof, means utilizing the externally accessible part of one of said shafts for rotating said article supporting means about the axis of said shafts, and means utilizing the externally accessible part of the other of said shafts for rotating said article supporting means about an axis inclined to the axis of said shafts.

8. In an electron optical instrument having an evacuated chamber, a positioning means comprising a pair of coaxial shafts extending within said chamber, said shafts having externally accessible parts, article supporting means supported by one of said shafts within said chamber, said chamber including a movalble portion, means for controlling the position of said movable portion to translate said shafts along the axis thereof, means for controlling the angular position of said shafts relative to said axis, means including one of said externally accessible parts for rotating said article supporting means about the axis of said shafts, and means including the other of said externally accessible parts for rotating said article supporting means about an axis inclined to the axis of said shafts.

9. In an electron optical instrument having an evacuated chamber, a positioning means comprising a pair of coaxial shafts extending within said chamber, said shafts having externally accessible parts, article supporting means supported by one of said shafts within said chamber, said chamber including a movable portion, means for controlling the position of said movable portion to translate said shafts along the axis thereof, means for controlling the angular position of said shafts relative to said axis, means including one of said externally accessible parts for rotating said article supporting means about the axis of said shafts, means including the other of said externally accessible parts for rotating said article supporting means about an axis inclined to the axis of said shafts, and means whereby the position of said article supporting means may be varied along said inclined axis.

10. In a positioning device for an electron optical instrument of the type having an evacuated chamber, the combination comprising a. pair of coaxial shafts extending into said chamber, a bellows surrounding said shafts and sealed to said chamber, whereby a portion of said shafts is maintained at the pressure within said chamber, said shafts having externally accessible parts, article supporting means supported by one of said shafts within said chamber, means for compressing said bellows to vary the position of said shafts along their axis, and means utilizing said externally accessible parts for rotating said article supporting means about the axis of said shaft and an axis inclined thereto.

IGOR B. BENSEN.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 314,775 Bailey Mar. 31, 1885 455,660 Cooper July '7, 1897 '975,714 Pfautz Nov. 15, 1910 1,916,609 Emmons July 4, 1933 2,372,422 Hillier Mar. 27, 1945 2,380,209 Bachman July 10, 1945 

